Some info: "This New City Landscape represents location based twitter activity as the tweetography of the city. The data is derived from tweets sent via a mobile device that includes the location at the time of sending the message. The contour visualises amount of tweets sent as the the density of tweets. The location names correspond with the real world counterpart. Data collected in October 2010."

The maps are a bit disorienting, particularly if you know the actual topography of a community as the analogous contour map is so evocative of elevation differentials. Not that I'm intimately familiar with the contours of Denver, but it's interesting to rethink a standard physical model in informational 'datascapes' that can be juxtaposed on the standard topographical base sheet.